Air mattress



FIG. 1 is a perspective view of a air mattress showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

Throughout the views, the broken lines represent the portions of thedesign that form no part of the claim.

CLAIM The ornamental design for an air mattress, as shown and described.